Top for me have to be the combo of Aniyomi and WVC.
Aniyomi is a Tachiyomi fork that adds anime extensions. Tachi is great as is, but after Anyme shut down, I needed something to watch and track anime with MAL integration. Plus if you read manga, I'd assume you watch anime too. App and extensions receive regular updates.
WVC aka Web Video Caster. Chromecast any video. I have watched soooooo much stuff on my TV through this. Great controls and features, frequent updates, and they're on Reddit to talk to directly if you have issues or feature requests. Great team of people and wonderful app. First premium app I bought.
Bring! is a close third. Works on Android and iOS so me and SO can both share a shopping list every since Google screwed theirs up. Was great when Google Assistant was linked to it, but Google broke that too. Still a great app though. We get notifications when the other person adds an item in case one of us is running errands already.