Apple is raising the price of apps in the UK, as well as India and Turkey as a result of exchange rate and tax changes.
In the UK app prices are rising by more than 25% following the further recent falls in the pound due to Brexit and the ongoing incompetence of the Conservative government. In fact such a price rise is assuming further falls in the pound against the dollar even with VAT factored in. An app sold for 99c in the US will now cost 99p instead of 79p.
Increases of about 25% are reflected all the way across the pricing matrix for the United Kingdom App Store.
Developers will be able to re-price their apps to new, lower tiers starting at 49p, but if they do nothing their prices will be automatically changed over the next 7 days starting 17th January.
There has not yet been an equivalent announcement regarding iTunes content like movies and books but it would seem to be likely to follow shortly.