PowerReader Lite vs VaultXT

PowerReader is a simple but powerful reading tool.
 Features: 
 - It is available to view the files with various formats as below: txt, pdf, png, jpg, tiff, gif, bmp, htm, html, doc, xls, ppt, docx, xlsx, pptx. - Supports landscape view mode. - Diverse kinds of encoding for txt reading. - Turning pages forward or backward quickly. - Uploading files through iTunes. - Automatic line breaks. 
 - Full text search, you can easily search the entire text. - Online Translation engine. - Automatically save the last reading point. - Automatically separate the big txt file to accelerate the access speed - More features in full edition: - It is also available to play mp3 & mp4 files. - Supports Google docs downloading. - Supports "Open-in" feature, you can open the supported data from mail, safari or some other APPs that supported open-in feature. - Various types of font for txt reading. - Text color and background color setting. - Bookmark feature. - Single/multi page display for PDF viewer.

VaultXT is a local editor for large text documents. It handles the text content of .txt, .md, .log, .csv, .json, .yaml, .yml, and .arb files. Edit large files in one continuous editor, use find and replace, and let autosave run after a pause in typing. Review and restore snapshots, organize documents in named, colored, nested folders with manual ordering, and create new drafts by splitting or merging documents. Format checks are available for JSON, ARB, YAML, and YML. They never block saving and may be skipped for large files. Imported files become local working copies, separate from the external originals, and you choose the destination when exporting. Editing works offline on your device. Free includes editing, 10 open documents, 10 documents in the Library, the 10 latest snapshots per document, splitting into up to 10 pieces, and merging up to 10 documents. Pro is a one-time purchase that expands these limits, with no subscription and no ads.