They are dozens of great, free software applications developed… the problem is getting the masses to use these applications.

A google Keep alternative where I can share certain notes with someone and have live collaboration on them.

An open-source, federated, and privacy-protecting alternative to the dominant advertising services. Something that gives the individual web user full control of which ads they see; from which indies, organizations, companies or any other groups. And where they can also filter ads based on clear categories, values, or tags, rather than everything being dictated by algorithms and "relevancy".

Well working, good looking airgaped password manager

There are some, but they are mostly like proof of concept

a shared calendar app!

A messaging app/service that can work via both regular stable connections but also via non-online. Briar is kind of similar to what I am talking about. But it can't/doesn't go as far as I mean. It can send messages via cell data, WiFi, and Bluetooth but as far as I am aware, it can't do a mix of them. And it would still require the person being messaged to be within range of my phone's Bluetooth if not on cell/WiFi. So it doesn't do the hopping I am really interested in (to my understanding).

So I am wanting to be able to have basically zero cell or WiFi signal on my phone, but be able to just have shit be able to bounce around via all methods to get to the person I am trying to reach. So like I could be in a no service spot for my carrier but maybe a friend that also has the app and does have a signal be used to bounce my message from Bluetooth to their cell or WiFi that is working. Then it either get to the final person from that bouncing, or maybe still get it if they are also in a no-signal area but still near another friend that does and is also in their Bluetooth range.

So the message would just hop whatever chain of devices and connections even if it takes a little more time (like if it just had to keep hopping from a number of phones completely through Bluetooth jumping. Would also be cool if it could jump even if the other devices didn't have the app and was just encrypted text-only blobs hopping like how data hops around various servers when online. But aside from the fact that data costs money and would mean basically everyone's shit would get used at all times. The nightmare of how the messages/service would know how to get places, or if maybe it already arrived via one method while a different chain was still trying would be massive. In addition to literally all the other things that would have to be figured out. And that is all before making sure it could be still private in any real way.

Ummmm, ALL of them.

Decentralized encrypted email.

Create a key, identify it by a hash of it, and encrypt all mail sent to the account with the key. Allow it to run on top of regular email using one or more email addresses as an alias, but have the key itself be the identifier.

Client 1 creates a key pair > uploads email address(es)/"aliases " that client controlls (signed with key pair) > client 2 searches for emails based on client 1's key or aliases > client 2 sends email through one or more of the accepted inboxes encrypted with public key > client 1 reads encrypted email.

Basically a modernized version of PGP that also handles identification, and similar to how it's been proposed to change Matrix accounts to in order to make them decentralized.

Project Management and CRM ecosystem -___- Who's down to make one. LOL.

Something like invidious and libreddit but for tumblr. Its currently borderline impossible to use tumblr without am account and it drives me NUTS! Ive been tempted to pay somebody for this at this point, im so desperate lmao

I'd love a self-hostable tool like trakt or simkl, to track my media consumption, as well as release dates.