AstroShader vs AstroFileViewer

One-time purchase. No subscription. AstroShader is an astrophotography app for capturing, stacking and editing. All you need is a stand, tripod, telescope or rock (to lean your phone on). AstroShader lets you align and stack live during the image capture process. You can also align and stack images from you Photos library. No need to transfer images to a computer to align and stack them separately (but there is a built in intervalometer if you need it). To take an image follow these steps: • Use a stand, tripod, telescope mount (or lean your iPhone on a rock). • Zoom in on stars and set focus manually, or use autofocus. • Set the exposure time, ISO and white balance, or leave to auto-exposure. • Set the number of exposures to be automatically aligned and stacked. • Calibrate your images from the edit tools. • After the capture is complete you can edit and save your image—including as 16bit TIFF. • You can open images directly to use the edit tools in AstroShader - rather following a new image capture. Image capture options include: • Number of exposures to be aligned and stacked • Exposure time • ISO • White balance • Camera type • Countdown timer • Manual focus • Pause the capture to reposition iPhone or telescope Edit options include: • Stretch image • Background extraction • Dynamic background extraction (DBE) • x5 Histogram curves for fine tonal adjustment • x3 sharpen layers each with radius and intensity with layer blending rather than chaining • Brightness (low light enhancement) • Saturation • Black point • Temperature • Tint • Save format options; HEIF, PNG, JPEG, TIFF

AstroFileViewer lets you open and view astronomical image files (FITS and XISF) directly on your iPhone or iPad. Whether you receive a sub-exposure via AirDrop, download one from Safari, or browse your imaging files in the Files app — AstroFileViewer displays them with a proper PixInsight-compatible STF auto-stretch so you can actually see what's in your data. Why stretching, gradient control and denoising on an iPhone? Simple. You get an early impression of how your data could look after post-processing. And it's simply fun too. Features: - Open FITS and XISF files from Files, Safari, AirDrop, email, Google Drive, or any share sheet - PixInsight-compatible Screen Transfer Function (STF) auto-stretch for proper visualization of linear astronomical data - Supports mono and RGB images from all major astro cameras, including OSC debayer (RGGB, GRBG, GBRG, BGGR) - Dark point slider — clip noisy backgrounds, just like AstroBlink on macOS - Contrast slider — S-curve with logarithmic response for fine control - Color saturation slider — boost Ha reds and OIII blues in your OSC data - GPU bilateral denoise — edge-preserving noise reduction, up to 300% strength - Gradient correction — auto-detects and removes linear light pollution gradients - Auto-rotate — landscape images automatically fill your screen in portrait mode - File history with swipe navigation — swipe left/right to flip through recently opened files, even after restarting the app - Recent files on start screen — thumbnail grid of your last 6 images for quick access - Tap-to-fullscreen — single tap hides all UI for distraction-free viewing - Pinch-to-zoom up to 10x with smooth panning - SNR and star count shown in the status bar - FITS/XISF header inspector — view all keywords with important ones highlighted - Save to Photos as a stretched JPEG with all adjustments baked in - Full compression support: LZ4, LZ4HC, zlib, zstd, fpack (Rice, GZIP), ByteShuffle - Persistent settings — all sliders and toggles remembered between sessions - Built-in help section — tap the ? icon anytime - All processing happens on the GPU. All sliders respond in real-time. AstroFileViewer registers as a handler for .xisf, .fits, .fit, and .fts files on your device. No account required. No internet connection needed. Your files stay on your device. Built by an astrophotographer, for astrophotographers.