If the app is a problem, there are options. Nostr is free and open source so there are different approaches.
You may try Gossip Nostr client - its a desktop application that you install, meaning its fast, its secure (all your private keys stay on your hard drive) and you set up everything yourself - choosing relays, who to follow, organizing the people in groups and so on.
It may take a bit to get used with all freatures but its awesome.
https://github.com/mikedilger/gossip/releases