As the title says, I built a very simple app to help with preflop studying (you can download it by searching for "donk poker" on the App Store or by clicking here from your phone:
https://apps.apple.com/us/app/donk-p...y/id6661016693). It lets you quiz yourself on what decisions to make with different hands in a variety of scenarios (currently supports RFI, facing RFI, and RFI vs 3bet). You can also choose to focus only on fringe/boundary hands if you prefer. The ranges are all from the PokerCoaching free preflop ranges, so they're not exactly GTO, but I figured they'd be a decent starting point. Let me know if you find it useful/have any feedback or feature requests!
