CrystalEngine: In-File Search

Overview

CrystalEngine finds files on Android by content, not name, and opens them in its own viewer; music, video, a gallery and file management are built in. Indexing and search run on the device, not a server.

Design and navigation

5.0.0 redraws every screen from one set of colors, shapes and type. Search, Files, Media, Trail and Settings sit in a bottom bar, a side rail on large screens. Each file type has its own color and glyph. The theme is Crystal, Amber or Mono, and light, material, haptic and motion effects can be turned off.

Search engine

The index covers document text (docx, xlsx, pptx, PDF, TXT, HWP, HWPX), text in photos and speech in recordings; the matching sentence is highlighted. Contacts and Calendar are indexed only once enabled in Settings.

Korean search matches partial words and initial consonants. Tests keep search within 58.4 ms on 100,000 indexed rows. New files are indexed on pressing Scan, or within 15 s once Automatic scan is on.

The operators are type:, filetype:, in:, intitle:, intext:, size:, before:, after:, exclusion (-), exact phrase (""), AND (&), OR and NEAR, so filetype:pdf quote after:2026-01-01 is one query.

The Korean text-recognition model is built in; transcription and image models download once, then run on-device. Terms can be spoken, and a photo or one region of it finds lookalikes on the device.

Document viewer

Documents open in-app in HWP, HWPX, PDF, docx, xlsx, pptx, TXT, MD, CSV and RTF, with find in document, bookmarks, a PDF highlighter, copy and share. Shadows, gradients, patterns and rotation in HWP, Word, Excel and PowerPoint are drawn as stated. A PDF stays sharp when zoomed, and its fonts, colors and transparency are read from the file. HWP renders in the app, as Korean public offices mostly use it. Dark view carries over.

Music and video

The music player has a 10-band parametric equalizer (PEQ-10) and a seven-module sound rack, with A/B against the original. The sound console has a normal and an expert mode, and the equalizer shows the current setting as a curve. Sound settings are kept for next time. Crossfade, gapless playback, ReplayGain and resume are there; lyrics stay on the device.

The video player has playback speed, SRT and SMI subtitles, brightness and volume gestures, picture-in-picture, resume and A-B repeat. Chromecast and DLNA devices appear in one list.

File management and archives

Copy and move show progress and can be cancelled. Deleted files go to the trash and can be restored, with large-file cleanup and a storage dashboard. Renaming a file updates the index; duplicates are shortlisted by size, confirmed by SHA-256.

Tapping an archive opens its list. zip, 7z, tar, gz, xz, zipx and more are browsed and extracted, password-protected and nested ones included, and documents, photos and music inside open unextracted. Only zip is created, with a password if wanted.

Trail gathers daily traces of photos, music and searches; call recordings and app usage stay off until enabled.

Processing and privacy

Indexing, search, text recognition, transcription and image comparison run on the device; search works in airplane mode once a model is downloaded. There is no account, and the index is stored encrypted. File contents are not transmitted off the phone.

Map tiles and model downloads use one network switch, on by default. Photo coordinates become an address via a system service if enabled. Voice search uses the on-device recognizer first and falls back to the system one, where audio leaves the device.

Terms of use

No persistent banners, interstitials or launch ads appear. The free trial ends at 5 launches or 1 hour, whichever comes first; one ad watched in full opens a 1-day pass, and a lifetime purchase keeps it ad-free.

Formats and languages

Verified on a device: docx, xlsx, pptx, pdf, rtf, md, csv, txt, hwpx. Languages: Korean, English, Japanese, Chinese, German, Spanish, French, Portuguese.

Contact: support@bsplanet.app

Recent changes:

What's improved:

• Tapping music opens the full player, or choose to start in the mini player in Settings
• Update notice redesigned to match the Crystal, Amber and Mono themes
• Fixed nearly finished songs and videos resuming at the end
• Fixed backup files with music extensions showing up in the music list and queue
• Fixed files with # or % in the name not playing
• Updated security and Chromecast libraries, other stability fixes