Here is an interesting review of an iOS app at TechCrunch. It is called Heard and it continuously records all the sounds appearing around you so that in case you missed something, you can easily go to the buffer and save the relevant portion. A good example, mentioned in the article, is something like, your baby has just said something and you wish you had recorded it.
The app has a free as well as a premium version. The free version lets you save the previous 12 seconds of the audio happening around you. Once you have purchased the app (it costs $1.99), you can save up to 5 minutes of conversations and voices.
When left to its own devices, the app keeps on recording the audio of whatever is being said or played around you and saves it in a buffer. Suppose you have set the buffer timer to 4 minutes. It automatically deletes the old the data in the buffer and goes on recording new sounds. Its unique audio algorithm enables you to simply tap the “Save” button and all the prominent sounds are saved and the data is cleared off the buffer. Later on you can rename the file, tag it, e-mail it and even share it on Facebook.
How is it different from the inbuilt Voice Memo Recorder that comes with your iPhone? The TechCrunch article doesn’t throw much light on this. A big difference might be that if you use the inbuilt recorder, it will go on recording without deleting data in the buffer. This app continuously deletes the older data. What about the effect on your battery? Anyway, this can be a good toy to play around with.