3D Solar System vs VoyaLang: which is better? (2026)

3D Solar System

Real-time 3D solar system simulator powered by NASA/JPL data, with eclipse predictions, live ISS tracking, and an AR SkyView constellation finder.

3D Solar System is a real-time 3D simulator of the solar system built on precise NASA/JPL orbital data. It shows the actual current positions of the eight planets and major moons, and lets you rotate, zoom, and follow any body in real time or at accelerated time scales. A dedicated Real Scale mode renders true relative sizes and distances instead of the exaggerated proportions used for visibility in normal view. The app includes a solar and lunar eclipse calendar covering 2024 through 2100, live tracking of the ISS, Hubble, and James Webb Space Telescope, and a near-Earth asteroid overview highlighting potentially hazardous objects. SkyView, a newer feature, uses the device camera, gyroscope, and GPS to match constellations to the real night sky above the user, with a constellation browser and time-travel controls to preview the sky at any date. Available as a web app and a native Android app, with Korean and English support.

VoyaLang

AI IELTS writing checker: Academic and General Training, Task 1 and Task 2, four band scores, line-by-line corrections, and a Band 8+ rewrite in seconds.

VoyaLang is an AI IELTS writing checker that scores your essay, corrects it, and rewrites it at the band you are aiming for. Writing is the section most IELTS candidates lose marks on, and it is the only one you cannot practice with an answer key. Reading and listening can be self-marked. Speaking can be rehearsed with a friend. An essay needs a trained examiner, and examiner feedback costs money and takes days to come back, so most people write essay after essay without ever learning what was wrong with them. VoyaLang gives you that feedback in under a minute. Every submission returns three things: 1. IELTS band scores on all four official criteria: Task Response, Coherence and Cohesion, Lexical Resource, and Grammatical Range and Accuracy, each with the reasoning behind it. 2. Line-by-line corrections, with every grammar, vocabulary, and punctuation error labeled by type so you can see which mistakes you repeat. 3. A rewrite of your own essay at your target band, so you can compare what you wrote against what a higher band looks like on the same question. What it covers: IELTS Task 1 and Task 2, Academic and General Training. Task 1 is handled per visual type, so line graphs, bar charts, pie charts, tables, process diagrams, maps, and mixed visuals each get their own criteria rather than one generic chart rubric. Task 2 covers opinion, discussion, problem and solution, two-part, and advantage and disadvantage questions. British and American English are detected and preserved, so your rewrite comes back in the variety you wrote in. Practice tools: A library of 1,400+ exam-style IELTS writing topics, filterable by exam type, task, topic, and chart type. Vocabulary sets by proficiency level. Per-criterion progress charts that show which criterion is holding your overall band down across submissions. Full writing history with PDF export, and a practice timer for exam-condition attempts. The band is a calibrated estimate, not an official result. It is designed so it cannot be talked upward: raising your target band changes the rewrite you receive, never the grade you are given. What it does well is explain why the score sits where it does and what to change to move it. Free to try, built for daily practice.