Most likely I am not going to use the mobile version of spreadsheets, but you never know. I know that from time to time, when I am sharing my Excel spreadsheet (or various subparts of them), it is fairly well presented on whatever applications are already on the Iphone. I presume android phones can also read my Excel spreadsheets, and in the past 10-20 years, we have come along way with cross-compatibility and even way less bugginess (or changes in format) compared to some of the earlier attempts at cross-platform-compatibility matters.
Yes there're alot of Microsoft software apps for mobile including Word,Onenote e.t.c
well there are alot of spread sheet softwares out there actually.. I use Android and there are tons of them on Play store and i believe this should hold same on Apple store..but to be specific i use Zoho can also recommend Microsoft Excel,Goggle Sheet, XLSX viewer , WPS (i'm sure Google sheet offer free service) and i believe they should be available on apple store.