OMR Sheet Scanner vs NL Sensor

OMR Grader turns your iPhone into a powerful answer sheet grading machine. Teachers, professors, and educators can create, scan, and grade multiple-choice bubble sheets in seconds — no expensive hardware needed. GENERATE CUSTOM ANSWER SHEETS Create professional OMR bubble sheets with 50, 100, 120, or 160 questions. Choose 2 or 4 column layouts. Add your school or institute name. Download as PDF ready to print on any standard printer. SET ANSWER KEYS IN SECONDS Tap bubbles on screen to set correct answers. Or scan a pre-filled master sheet and the app creates the answer key automatically. Set custom point values per question and penalty scoring for wrong or multiple-marked answers. SCAN AND GRADE INSTANTLY Point your camera at a filled answer sheet for instant grading. The app detects the sheet, reads every bubble, and shows the score in real time. Works with printed sheets from any standard printer. BATCH GRADING FOR LARGE CLASSES Have a stack of 100 or more sheets? Use any document scanner to digitize them, then load all images into Batch Scanner. The app grades every sheet automatically — saving hours of manual work. VIEW DETAILED RESULTS See each student's score with a color-coded annotated sheet showing correct, incorrect, empty, and multiple-marked answers. Identify which questions students struggled with most. EXPORT AND SHARE Export results as CSV spreadsheet, PDF report, or ZIP archive. Share with colleagues, administrators, or parents easily. PREMIUM FEATURES Free users get 20 scans per day. Upgrade to OMR Grader Premium for unlimited scans, batch grading, and priority support. Privacy Policy: https://omrgrader.com/privacy Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

NL Sensor turns your iPhone or iPad into a live dashboard for Nu Lambda Scientific Bluetooth sensors. Connect a sensor, watch the data stream in real time, analyze it on the spot, and export it — all on device, with nothing sent to the cloud. MEASURE ANY SENSOR IN THE FLEET • Motion / distance, force / load, voltage, current, pressure, illuminance, 3-axis magnetometers, dual-thermistor temperature probes, and photogates are detected automatically by name. • Metric cards show the current value and a stable 40-point average. • Set the sample rate from 1 to 100 Hz right from the app. LIVE CHARTS BUILT FOR THE LAB • A smooth 10-second sliding window while you measure. • Pause to pan and pinch-zoom — each axis zooms independently, so you can stretch time or values on their own — then show all data, reset, or clear. • Drag to select a region and get a least-squares linear fit (slope, intercept, R²) or statistics (mean, standard deviation, count). • Expand any chart to full screen. MOTION, VELOCITY & ACCELERATION • Motion sensors add derived velocity (m/s) and acceleration (m/s²) charts, computed with smoothed derivatives. PRESSURE & TEMPERATURE • Pressure sensors add a Temperature-vs-Time chart and a Pressure-vs-Temperature graph, with a fine ±0.1 hPa scale for reading small changes. DUAL TEMPERATURE • Dual-thermistor probes show T₁ and T₂ together on one chart plus a separate chart for each, colour-coded red and green. PHOTOGATE EXPERIMENTS • A photogate sensor turns beam-block timing into seven ready-made experiments: Basic Free Fall, Single Gate, Two-Gate Timer, Pendulum Period, Speed (two-stripe card), Pulley, and Two Gates. • Get distance–time and speed–time graphs, oscillation periods with average and spread, angular motion from a pulley, and precise gate timing — then linear-fit a speed–time graph to read acceleration straight off the slope. WALK THE GRAPH • Turn distance-time graphs into a movement challenge: pick a target curve, walk to match it, and get a live score for how well your motion tracks the graph. Five graph sets from basic to creative. TWO SENSORS AT ONCE • Connect two sensors and compare them on an XY chart that pairs their latest readings in real time. • Pause the XY chart to pan, pinch-zoom, drag-select a range for a linear fit or statistics, and tap any point to read its A / B values. TONE GENERATOR (NO SENSOR NEEDED) • A built-in signal generator, open straight from the dashboard. Play a pure sine tone from 0.5 Hz to 20,000 Hz with a slider, exact numeric entry, and a fine/coarse adjust pad. • Run a frequency sweep (chirp) with your own start, final, step size and step duration, and a live progress bar — great for hearing tests, resonance hunts, and Doppler demos. • Switch to Dual Tone to sound two independent tones at once for beats, musical intervals, superposition, and masking. Set amplitude and output channel (both, left, or right) for each tone. EXPORT EVERYTHING • Export any chart, the XY data, or the entire session as CSV through the iOS share sheet. PRIVACY • All measurements stay on your device. No account, no tracking, no data collection. NL Sensor requires a compatible Nu Lambda Scientific Bluetooth sensor. A built-in demo mode lets you explore the app without hardware.