By Graham K. Rogers

I had a chance over the weekend to look at a couple of interesting photo apps: Noir Photo, an old favourite returned; and TinType, which was new to me but has been around for a while. Both are well worth downloading. While looking in the iTunes app store, I also found RebelSauce. This is a free app and I was attracted by its unusual name.

It has an opening screen that hints at quality with a slide show of some sharp photographs. A nice touch is that the large white name icon can be tapped and it becomes transparent so the slide show can be seen more clearly. As with many apps there are two input options, Camera or Photo Library.

Importing an image opens it with a selection of "Sauces" or filters shown underneath: each a thumbnail of the original, so that the potential is already apparent. Selecting one by tapping applies the effect. Tapping the icon again, removes it. Touching the main image with the filter applied, shows the original while the finger is on the screen.

Scrolling the filters left and right shows a fairly good selection in the app's free state. If the filters are scrolled up or down, other filter sets are shown and these may be purchased for $0.99. All the sets are shown as available for $5.99.

Below the image and filters the word, "Sauces" is displayed. Tapping this reveals a panel with several editing tools available.

• Screen 1 has Saturation, Brightness, Contrast, Vignette, Sauces, Expiration, Fade, Rotate & Crop, and Grain.

• Screen 2 has Fix highlights, Fix Shadows, Vibrance, Temperature, Tint, Sharpen, Tint highlights, Tint Shadows (both with color selectors) and Skin Tone.

Several of the controls, including Sauces, have sliders to adjust any effect selected.

Either side of the editing effect name (e.g. Temperature, Sauces) is an arrow. Left takes the user back to select a new image. There is a warning that any changes to the current image will be lost. The right arrow reveals a panel for saving and export.

The edited image is saved to the library automatically when this page is accessed. In my setup, Twitter, Facebook and Instagram were available on the panel, but also others that I was asked to sign up for. Saved images were in the library with the same date as the original. These images also retained metadata including GPS information.

The app was marked in the iTunes App Store as "iPhone Only" but I tried it on the 9.7" iPad Pro. Using the x2 upsizing feature, the display was clear enough and the app was certainly usable - losing nothing here against the iPhone installation - but loses something in the crispness of the screens. I hope that the developers make the app universal.

The filters available in RebelSauce are not particularly revolutionary, but provide a selection of subtle effects. These will suit many users who want to make edits to their photographs without the need for radical changes. The range of editing tools available in this free app makes RebelSauce a useful starter app, although those familiar with more sophisticated apps will also find something of value here.

Like the other apps mentioned above, RebelSauce has been around for a while. I recommend having a look at this.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs. He is now continuing that in the Bangkok Post supplement, Life.