InboxFee is a mobile app that connects to your Gmail account. Whenever you receive a cold email you can reply with an 'inbox fee invoice' saying 'pay a small fee if you want me to read your stuff'. Payments are processed over Bitcoin Lightning Network.

Smart search for the files on your phone. It detects text on images, so you can search through pictures of documents, screenshots, memes, etc. It also converts speech to text in audio and video, and makes stuff like voice messages and movies searchable too!