After 6 months of inactivity a giffgaff sim will be deactivated. At present the only way to find out when this will happen is to check your call and text logs, work out when you last topped up (source), or wait for an email from giffgaff warning you of your sim's impending doom (source).
I would like to suggesst a Sim Activity Checker for the dashboard/My giffgaff page. This could simply be a link to a page showing 2 dates: one for when the sim was last considered active, and another for when the sim is due to expire/become deactived.
I spend quite a lot of time overseas, and I selected giffgaff because of its flexibility. I love that I can get a contract-like deal for my sim for just a month or two at a time, and avoid paying over the odds with payg or getting a contract that I simply won't use. I can only imagine that there are many other users just like me.
Being able to check sim activity for intermittent but committed users like myself would be a real help. Not only will it help us to avoid losing our numbers and credit, but it will also give us a quick and easy way to check our sim's activity and put our minds at rest, without having to scramble around for call logs or emails.
I hope you like this idea and can show your support.