it is based on a very common CPU; the nRF52832 and therefore easy to develop for; I do not have the PineTime (or devkit) myself, but made one according to the schematics and BOM for development.
As someone with a PineTime Dev Kit on their desk in front of them, I would say that “just not sealed/glued shut” is not the entire story. Sure, you could glue it shut. But you would be stuck with somewhat bog standard software that is neither exciting nor updateable unless you hook the device up via Serial Wire Debug (SWD) to flash it – which requires yet another piece of kit to achieve. PINE64 are not joking around when they state that: “The PineTime Dev Kit [is] aimed solely for development purpose only, this is not for end user[s] who [are] looking for [a] ready to wear Smart Watch. More specifically, [we] only intend for these units to find their way into the hands of developer[s] with extensive embedded OS experience and an interest in Smart Watch development.” [1].
That being said, I have had a lot of fun learning embedded systems over the holidays and highly recommend getting a dev kit if you want a rewarding hobby that is likely to contribute to this watch coming out “for real” with a lot of fun software some time next year. Admittedly my reading list is very Rust biased, so feel free to ignore parts of it. But I highly recommend the embedded Rust “Discovery Book” [2] and “The Embedded Rust Book” [3]. Also, anything written by Lup Yuen Lee (李立源) so far has had the highest quality of all writing related to PineTime development. The only downside is that it is on Medium (yuck!), but do start with the one where he breaks his PineTime open for the first time and go from there [4]. There is also of course the PineTime sub forum [5]. Lastly, if you are new to embedded systems (such as myself) it may also be worth getting the development board that corresponds to what is inside the PineTime [6]. Happy reading and hacking!
You certainly can, I just have not tried it. It comes with a strap and everything. User “maiden” has an awesome setup that makes it both flashable and wearable for testing, have a look [1].
https://store.pine64.org/?product=pinetime-dev-kit