Amazing how people's data gets a whole lot more important once it's not there anymore!
When it comes to data recovery, the first thing to bear in mind is that there are no guarantees. Data that's gone may very well be gone for good, especially if the device has been used since the file or files were deleted and new data has overwritten it.
However, nothing ventured, nothing gained (or lost).
The tool I've been pointing iPhone, iPad, and Android users to is EaseUS MobiSaver. MobiSaver comes in free and pro versions available for both iOS and Android.
The iOS version supports to directly recover deleted or lost SMS, contacts, pictures, videos, WhatsApp history, documents and so on from iPhone, iPad, iPod touch and iTunes backup. The Android version supports to recover data from Android phone/tablet such as Samsung, LG, HTC, Motorola, Sony, Google etc.
Both versions are pretty easy to use, and I've heard back from people who have used them to recover data.
Personally, I'd much rather have a backup regime that I can fall back on, but failing that this tool could offer you a fighting chance.