I could not find this anywhere on the site so delete if already posted. We are moving house next week and instead of ringing British Gas to tell them I used there app.
As you go through the moving process via the app, as a little thank you for staying with them (we are as we on cheapest tariff thanks to MSE) they offer you either a free boiler service (worth £89) or a free Hive smart light starter kit (worth £119) which includes two bulbs and a router kit.
I opted for the Hive kit seeing as I pay monthly for a service through another provider.
I know it's very limited on who can have this but useful to know I thought, hence the post. Hope it helps someone.
I've since tried to find a reference on their website but cannot, so it must be exclusive to app