To the OP
There is no requirement, by SAFA, EASA or ICAO that requires you have an "approved" logbook. All that matters is that you have it in the approved format. An excel spreadsheet is perfectly adequate. It may be that some remote countries don't believe that LogTen Pro is suitable but certainly the UK CAA does and almost certainly any EASA/FAA/TCA controlled territories will be.
That it be presentable on demand is open for debate, I don't carry mine with me, it would get wrecked! So I use Log Ten Pro, print out then sign and stick it in my logbook
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HTH