The first thing to check is whether your former employer has a need for part time. Both parties are validated, and there is little to no ramp up needed.
The next I'd look at is mobile development. Now that there are multiple platforms to support (iOS/Android/WinMo), the demand for part time specialists is huge. There are a lot of companies that support a subset of those platforms but would like to add more (if they only had the expertise).
The next I'd look at is mobile development. Now that there are multiple platforms to support (iOS/Android/WinMo), the demand for part time specialists is huge. There are a lot of companies that support a subset of those platforms but would like to add more (if they only had the expertise).