On mobile, there are a couple FOSS options, but they all kinda suck, so I use obsidian with a todo.txt plugin that works pretty well for viewing and checking off items.
Just looked at Sleek (which I hadn’t heard of before) and looks pretty good. Thanks. I’ve been using the Obsidian plugin which has been fine up until now.
Yeah, and doesn't support (coming soon apparently) mobile extensions so no feature parity. But what stopped me from using Joplin for tasks was the unreliable alarm.
Joplin is pretty good as a lot of other stuff though.
For saving things like we pages, take a look at ArchiveBox.
It saves to your own server, and you can either link to it or copy the page to Joplin.
I'm currently using it to save pages from browsing on Android, using a Macrodroid macro to send the link to a text file that's synced to my ArchiveBix, which reads the file once an hour and archives the links in there.
I used to save everything to OneNote (I'm currently testing Joplin), and it got to be cumbersome on the phone, and have had OneNote disconnect from my Onedrive, meaning stuff stops syncing.
Tasks.org for all the important things that I need synced proper. Logseq for work and personal stuff, where i put all my ideas and info i've learned. Nextcloud notes for my digital post-it notes, like shopping lists. :)
I need to make it a priority to give logseq a try. I moved from Joplin to obsidian.md a couple years ago, because i realized an open data format (plaintext markdown files) was more important to me than an open source app (because I can still easily query and manipulate my data with open source CLI tools). I think at this point if I can replicate about 75% of my obsidian workflow in logseq, I'll make the jump and adapt my workflows to logseq's strengths and capabiities.
I think both are equally great and it's more about taste.
Logseq is an outliner, so basically everything is written in bullet points. For my type of thinking, that's great.
Obsidian is more about longer notes.
You can archive both with extensions, so it's about you what you prefer.