Since you're working on an iOS companion app, this seems like an appropriate time to mention the primary obstacle that has kept me off of the Gmail iOS app: it

Since you're working on an iOS companion app, this seems like an appropriate time to mention the primary obstacle that has kept me off of the Gmail iOS app: it doesn't support links in email signatures. I still find that hard to believe, and it's a deal breaker. IIRC, the Gmail app doesn't support signature formatting at all. Please do.