Your favourite apps?

We're putting together some advice and tips about technology and wanted to see what gransnetters thought were the best smartphone apps out there. Android, iPhone or any others you use are all fine.

Are you a games addict? Or do you have some great food apps that have changed the way you cook? Whatever you use that you think is really great, we want to hear about it.

Thanks!
<waits patiently for responses with finger hovered over app store>