There are a variety of electronic log books out there. All of them have different options and pluses and minuses. I don't have a preference on any of them.
From a check ride prospective, a pilot examiner must determine the applicant meets the requirements for the certificate and/or rating applying for. Flight and ground training must be logged in a log book (or training record) with a description of the training and the signature and certificate number of the CFI.
I've had a couple of applicants show up with an electronic log book. Nothing wrong with that. However, the entries for the training flights did not include a description of the training and, in one case, missing the signature and certificate number of the instructor.
Also, ground instruction is required to be logged as well. I'm not sure how this can be logged in a electroic log but an examiner will be looking for that too.