A fun game if you like music.
An app that plays some characteristic part of a song or music piece (the beginning few seconds, the bass line, etc.), and you have to identify it as quickly as possible. You can invite friends to a challenge. Leaderboards show the best overall, by music genre, decade, etc.
Document and quickly reference your work in the future when you need inspiration.
Use a content management system (can even be a private WordPress blog) to store the swipe file you write: emails, landing pages, etc. Tag each with the specific descriptors, so later when you need inspiration, you can easily and quickly find old/new ideas.
You are looking for a new gardening, cleaning, auto repair or other professional services.
Take the old model of asking your friends to a new level by having an online search functionality where you can ask a question like “show me a short list of all plumbers who have good reviews from my online friends.” This can be built on top of an existing social platform, by having a professional service review option. Professional services can have a presence (a company page on Facebook for instance), and people who use them can leave reviews. When you look for a new service provider, the system can then show you the top list based on people you trust – your online friends.
You go into a large multi-level parking garage, and would like to know where are the free spaces.
Each car entering is given a reusable parking card with dual functionality: use it to pay and exit, and it will show you on a map (a small screen) currently where you can find empty spaces to park, and where you are. It’s a live map guiding you to the available spaces.