I’ll say right away that these impressions are very subjective - really respect the author, contributors and entire community for pushing such a geeky project all the way to small production batches, and will keep supporting them in every way.

Had around a dozen Casio watches and several smartwatches of different concepts (Apple Watch/Garmin/Huawei/Xiaomi). But will mostly compare it with its direct competitor, the ABL-100.

Shipping and presentation were easy, it arrived in a couple of weeks. I ordered the already assembled watch - the packaging was very neat, inside there was a nice stand with the Ollee logo and the watch, the original module was carefully placed in the stand together with the instruction in a sealed electronics zip bag. When picked it up and unboxed it right there at the post office, it felt like a small holiday.

App: 1.0.5, FW: 00.01.07, HW: 01.05.00, 2026.06.16

Functionality:

• App - pleasant, decent UI and fast pairing (iOS). Cool animations with detailed explanations and the detailed FAQ on the website are very nice, but I would still like a separate Manual like Casio/Teenage Engineering and other companies have (at least on Github). Of the downsides, I’ll note the lack of a dark theme, but it seems like they promised to add it.

• BT Sync - a base thing for Casio watches, which really like to drift back and forth, works not as stable as on Casio, but well. By the way, I have absolutely indestructible Hamilton Pulsar watches that drift by a couple of seconds per year - sometimes I remember this and get sad about this unreachable accuracy for the cheap modules of most watches.

• Step counter - I didn’t check the accuracy properly (I have high-accuracy mode enabled and by eye it seems accurate), but it’s a nice bonus, especially direct integration with Apple/Google Health. I’ve seen posts where people complain about the accuracy, but for me in general it’s an optional thing if your phone is always with you and tracks steps more accurately. In the direct competitor ABL-100 we have constant step display with an awesome graph, which is much more convenient (its step tracking is also debatable, by the way).

• Temperature - 100% gimmick. Some outdoor activity lovers say that it’s supposedly important, but first of all, you probably won’t go hiking only with this watch, and secondly, a cheap smart sensor/thermometer will solve the issue much better. Since there is no sleep tracking and temperature analysis like in smartwatches (which track, for example, temperature symptoms that you are getting sick), I don’t see much sense in it.

• HR - well, this is a joke of course, I can hardly imagine who will manually enter their pulse after measuring it with fingers old-school style. Honestly, I’ll say that I don’t use this even on Apple Watch - the only ones who implemented it properly are Garmin, where it is shown live right on the screen and measured 24/7 (and even there, stress based on HRV is more interesting than just raw pulse).

• Alarm - only one, which is weak compared to the same Casios, but I know Multi-alarm is in the backlog. Snooze is a very cool thing, but works strangely (some buttons turn it off, some trigger snooze), and flipping the watch simply doesn’t work. Weekday splitting is convenient, but melodies look like a gimmick - the beeper squeak is just unbearably nasty in custom melodies (some people want volume control, but to me that feels too much). In any case, for me, as a person who is used to not disturbing others with vibration alarms and to tracking sleep on a watch/band, this functionality is optional.

• Hourly Chime - it is OP that you can set active hours. But for some reason you can’t set an interval that crosses 00:00, like 14:00 - 02:00, I hope they fix it with an update.

• Stopwatch. Not a very needed function for me, result logging looks interesting, but not mandatory at all.

• Timer. Nice implementation with time presets. It’s great that there is an interval one and you can implement something like Pomodoro.

• Counter - interesting functionality, potentially can be useful for religious people or for practical purposes. Personally, I didn’t find a use for it. Same as in Stopwatch, there is a counter for storing results on the phone.

• Games. Looks like a gimmick for me. If Pong (Game A) is very simple, then BlackJack (Game B) and Poker (Game C) look like theoretical entertainment for the most remote and lonely places, the main thing is that the terrible F91W buttons don’t rub your finger pads bloody. The very fact that games run on these watches, of course, I like.

• Sunrise/Sunset - my favorite functionality, which is extremely missing in Casio watches. Very convenient when you want to understand whether you still have time for golden hour. This is the only thing I left in the menu to have a second shortcut to it (the first one is steps on a long press of Flashlight).

• Backlight - a lot better than on native F91W: you can turn the backlight to maximum and at least it becomes convenient to check the time, also different regimes like toggle mode that let you use it when changing WatchFaces are dope.

• Backlight modes/color. Let’s be honest, even the very bright backlight of top Casio models is not enough to work as a real flashlight. Here we are dealing with an upgraded version of the one-sided F-91W backlight, which barely lights up a few centimeters of radius in the dark. You’ll play with it a couple of times and forget about it.

• Gestures/Gyroscope features. Taps and tilts for enabling different functions never worked well for me even on smartwatches, but here I find them absolutely useless. Putting them into the trinkets pile.

• NFC tag - it is so hard to find with a phone scanner that for me it turned out absolutely useless, because none of my phones without a case can read it. (UPD: make it work flawless with some of skill on Androids, but my iPhone still do not want to read it)

Features

• Audio mute - super useful feature, you won’t annoy your household with beeping.

• Shortcut for the Flashlight button - you can assign one of the WatchFaces to it (step counter/timer or whatever).

• Change order - changing the order of WatchFaces in the menu - I really missed this in Casio, very convenient. I hid everything except one, for quick access.

• Clock format locked in the app - disabling switching between 12/24h format, I didn’t have original F91W watches, but probably this could be annoying.

• Disable face timeout - cool feature for the step counter for example, but it doesn’t work for me - the screen in any case rolls back to the standard one despite this setting.

• Custom weekday names/week format - very convenient and useful feature for some countries, you can assign not only the order, but also Latin letter labels.

Downsides

• Closed firmware and app sources make full community work and hacking impossible, I read that the author wants to fix this in the future and I will very much welcome it: https://www.reddit.com/r/olleeWatch/comments/1lzhwyt/comment/n3rpy5m/

• I don’t really understand the roadmap. Yes, there are some blog posts, but in the comments people with insights about what will be done constantly appear, while there is no voting for ideas and no general availability of it.

• Without creating an account, you can’t view steps and temperature, and stopwatch/counter data also isn’t saved. This is an absolutely artificial limitation from the developer and I don’t like it.

• When motion tracker is enabled, the watch turns off, which honestly annoys me, because I often use it as a desk clock, and this behavior can’t be changed without turning the gyroscope off completely (yes, the toggle is ignored).

• The F91-W display is extremely limited in possibilities.

• There is no phone finder function, like on all BT Casio models (watch finder could also be there).

Not tested

• Battery: I use the watch regularly, I always have the step counter enabled with accurate counting, the backlight is turned to maximum and Bluetooth is enabled (I’m annoyed by constantly connecting manually from the watch, so I turned it on). For now it is unknown how long they will last, but it would be fun to try some kind of CR2032 mod: https://www.reddit.com/r/casio/comments/13y1pbi/f91w_20_years_battery/. It will be interesting to compare with the same ABL-100.

• Water Resistance - the official website warns that you should remember this is not a G-Shock!

Conclusion

As modified F91W, these are very cool watches, and I bought them exactly for this. But if someone asked me what good reliable watch to get with a step counter and BT time sync, I would of course recommend the ABL-100 - they are much more convenient in terms of UX, easier to get, and the price is quite comparable. Yes, they are more boring and not as geeky, but for basic things they will be more than enough.

For the project, I would wish a bit more openness in terms of development and building up experience for version 2.0 - I think with a really good MIP screen, this could become an insane Pebble Watch alternative for geeks.