there is new apps every week... but iris has been around a while, i quite enjoy amethyst as it has a good amount of features, like chat and livestreaming and the antispam works really well

the most important thing is a good mix of relays, not enough and you miss parts of nostr and too many slows your app down, relay selection is being automated too but only some apps have that yet, i recommend the relay relay.mostr.pub which bridges nostr to mastodon aka the fedi, they have 13 million users which adds variety beyond bitcoin lol