I've got an app that does a bunch of stuff all to do with signal strength (wifi and cellular).
It plots cell towers on a map. Shows you the direction signal is coming from. Graphs signal. It's great for improving your signal strength (simply walk towards the tower sending you data!).
We really need to test on CDMA phones before we can release this, because CDMA works pretty differently to GSM. We've tested on a Samsung Intercept (CDMA), but we need more people to check it's working on other models (like Droids on Verizon).
We want to use the app to build a public map of signal strengths so underperforming networks can be identified.
If you would like to help us in this project please get in touch!