The amount of storage space on a mobile device often sounds extensive when you first buy it, but if you're like us you'll soon fill it - especially if you are a habitual photo or video taker. And that's usually okay for Android phone or tablet owners as they often get the ability to extend the capacity through a microSD card.

iPhone and iPad owners are more hamstrung however. We have found that even with a 128GB iPhone 6 Plus or iPad Air 2 we've easily filled either device's internal drive to the max, with our own pictures, video clips and imported TV shows and movies to watch while travelling. And Apple does not provide card slots for expansion.

That's why the Leef iBridge Lightning and USB flash drive is a God send. It plugs into the Lightning port at the bottom of the more recent iPhones and iPads and offers significant upgrades to the amount of storage space available.

There are drives from 16GB to 256GB, so available at price points that suit all, and we've been road testing the 64GB version for the last few weeks to see if it really gives us more freedom. We can safely say it does.

The iBridge works with a dedicated iOS application, which is prompted to download the first time you plug it into your mobile device. This then gives access to different features of the drive. You can take pictures directly through the app, for example, which are automatically stored on the stick, or you can choose to transfer images to or from your Photos library on the Apple device.

Indeed, you can transfer any compatible files back and forth, including video. And as the iBridge comes with a conventional USB 2.0 adapter at one end, you can use it to transfer files from a computer to your iPhone or iPad very simply.

The last feature is the one we've found the most use for on our travels. You can store external video files on the drive and play them through either a built-in video viewer, if they are in a format natively recognised by the iBridge software, or through a third-party application thanks to an "open with" function.

We therefore copied over some TV shows we'd ripped from DVD in AVI format using our PC and played them running off the Leef iBridge without having to copy them onto our iPad storage. Apple-friendly MP4 files also played straight away and the app even recognises MKV files.

The same can be said for a myriad of document and music files.

As it has a peculiar shape to keep mainly out of the way when plugged in, the device comes with a "J" shaped cap to keep it free of dust or damage. And this also means it could easily be attached to a lanyard if you need to keep it close at all times.

The Leef iBridge is not particularly cheap, starting at £50 for the 16GB model (around £100 for the 64GB we trialled) but as it can even be used to more quickly transfer files between an iPhone and iPad than through a wireless connection, it could be a worthwhile investment for those with multiple Apple devices.