I presume you mean flush mounting wall sockets - A few around at £££
Last week I saw the Siemens branded (Lightwave RF/JS Design???) units reduced in price a bit at well known large DIY outfit (recently mentioned above) - Still far too expensive.
Lightwave RF units are also available in the (former) electronic component retailer, now purveyor of electronic tat, with annoying shop assistants.
just looked on ebay - HomeEasy double sockets for £13 - less than half the price I saw of above mentioned units
Note - IIRC, Lightwave RF operate at 866MHz - Can't see an android app, but Fanbois are definitely catered for. A match made in heaven.
HomeEasy/Byron etal operate at 433MHz