apps / apse are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
apps: NA
apse: (noun) a domed or vaulted recess or projection on a building especially the east end of a church; usually contains the altar.
apps: AE·p·s
apse: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)